The invention relates to a conductive device having contact portions that are independently displaceable so as to provide improved contact with another conductive device.
Conductive devices such as printed circuit boards (PCB""s) are used widely in the computer and electronics industries to transfer electric signals throughout an apparatus or from one apparatus to another apparatus. Each PCB includes a plurality of conductive or signal traces disposed on a substrate, and each trace has a contact portion that mates with a contact portion of another PCB so as to electrically join the PCB""s together.
An important and continuing goal in the computer and electronics industries is that of increasing trace density and bandwidth of such PCB""s. A limiting factor for increasing the trace density, however, is the ability to align and then force together the contact portions of one PCB with the contact portions of another PCB. For example, as the spacing of contact portions decreases, variations in height of adjacent contact portions on each PCB is more difficult to overcome so as to mate the surface profile of the contact portions of one PCB with the surface profile of the contact portions of another PCB. More specifically, as the spacing of contact portions approaches the thickness of each corresponding substrate, the forces needed to deflect the substrates in order to mate the surface profiles of the contact portions becomes significant.
The invention provides a conductive device and a method of manufacturing a conductive device that address non-coplanarity of adjacent contact portions.
A conductive device according to the invention includes a substrate and a plurality of conductive traces supported by the substrate. Each trace has a contact portion. Moreover, sufficient substrate material is removed from the substrate to sufficiently lessen stiffness of selected ones of the contact portions so that the selected ones of the contact portions are independently displaceable with respect to each other.
Preferably, the substrate has an aperture disposed between two adjacent contact portions so that the two contact portions are independently displaceable. In one embodiment of the invention, each of the two contact portions includes a plurality of laterally extending projections, and the aperture extends between two projections of each of the two contact portions.
A conductive network according to the invention includes a first printed circuit board having a first substrate and two first conductive traces supported by the first substrate. Each first trace has a first trace contact portion. The network further includes a second printed circuit board having a second substrate and two second conductive traces supported by the second substrate. Each second trace has a second trace contact portion. A bridge layer is also provided, and the bridge layer includes a bridge substrate and two bridge conductive traces supported by the bridge substrate. Each bridge trace has first and second bridge contact portions in electrical communication with first and second trace contact portions, respectively, for electrically joining the printed circuit boards. The bridge substrate has an aperture disposed between the bridge traces and extending sufficiently between the first bridge contact portions so that the first bridge contact portions are independently displaceable with respect to each other.
Further according to the invention, a method for manufacturing a conductive device includes forming a plurality of traces on a substrate, each trace having a contact portion; and removing a sufficient portion of the substrate between at least two adjacent contact portions so that the at least two adjacent contact portions are independently displaceable with respect to each other.
Preferably, the removing step includes forming an aperture between the at least two contact portions. Furthermore, the removing step preferably comprises removing the portion of the substrate with a laser.
More specifically, a method according to the invention for manufacturing a conductive device includes forming a plurality of traces on a substrate, each trace having a contact portion, the contact portions cooperating to define a template. The method further includes ablating with a laser selective portions of the substrate that are not covered by the template so as to form a plurality of apertures, wherein each aperture is disposed between adjacent contact portions so that adjacent contact portions are independently displaceable with respect to each other.